Vicarious Atonement
by Tentaspy
Summary: This is the story of how my Karthus became what he is today. It is all Headcanon, none of this story is in any way supported by lore, besides the fact that he willingly gave himself to The Shadow Isles. There will be plenty of emotion, romance, and smut. You have been thoroughly warned. Fic title is from a song by The Mars Volta.
1. Fear and Delight

Another day, another trip to the library of Demacia. The priest would resume his studies, gathering up an armful of books to skim through. Today, he found several books on folklore revolving around The Shadow Isles. The first book looked weathered and old, its spine was broken in several spots and a few of the pages were falling out. The faded image on the cover featured a strange centaur-like beast, clad in armor and wielding a sharp halberd. Though the creature looked fierce, it was drawn in a rather cartoonish style. Unfortunately, most of the books regarding the Isles were all just silly stories meant to scare children. Even so, he wanted to gather as much information as possible. After all, most fairy tales were at least somewhat true.

After he had loaded himself up with a pile of books, he begins making his way back to his favorite corner. He held the books to his chest, holding them in place with his chin. He begins walking delicately, trying not to tip over the tower of books. Rounding the corner he suddenly collides with another person, falling back and dropping his armful of literature. The books scatter across the floor, and he scrambles to gather them again.

A thin hand reaches for his shoulder, "Are you alright, sir?" He glances up, his eyes meeting the form of a young woman with long dark hair and piercing blue eyes. He had never really cared for women... but she was downright gorgeous.

"I-I uh..." He couldn't help but to stutter in her presence. "Y-Yes, I'm fine." He quickly glances back down to avert his gaze, but she kneels down next to him, smiling.

"Let me help you with these." She begins gathering the books as he stares at her dumbfounded, glancing over the titles. "Mm, reading up on the Isles, I see." She stops, picking up one of the books. "This one is good, but it's missing a lot of its pages."

He returns to lucidity, glancing at the book she held. The picture of the centaur stares back, but his eyes wander back up to her face. The priest could feel his face burning in embarrassment.

The woman suddenly brings her hand to his face, cupping his chin and running her finger over his cheek softly. "Are you sure you're okay, dear?"

He could feel his entire body shiver in delight as she touched him, her silky smooth fingers like icy feathers on his skin. His cheeks burned even brighter, and although he opened his mouth to speak, his words just would not come out.

She smiles a bit, "Mm, I think you'll be fine." She removes her hand, "Well, if you need any help, don't be afraid to ask." Carefully she sets down the books in a neat stack, standing up and turning away.

The priest finally catches his breath, "W-Wait, miss...?"

She turns back his way, her cloak fluttering. "Hm?"

"Could I, uh, ask you some things about the Isles? I'm... researching them." He gathers himself, finally standing up.

She smiles a little, "Sure, I'd be glad to help." She holds out her hand, "I'm Claudia. And yourself?"

"Aven." He says simply, taking her hand. Touching her felt literally magical... Was she some sort of sorceress? Hopefully not a siren, or a succubus...

"A pleasure to meet you. It's always nice to chat with another enthusiast." She takes half of the stack, handing it to him before taking the other half. "Where shall we sit?"

The priest holds the books to his chest carefully, glancing around. "I like sitting in the back corner, if you don't mind."

"Sure, sounds fine." She begins walking back to the mentioned area, taking a seat on one of the plush couches. The priest follows suit, sitting across from her and setting the books on the table between them. "So, where would you like to start?"

The two talk for hours about the Isles. Since this was something he was interested in, he was temporarily able to suppress his terrible attraction to her. He was asexual, but that didn't keep him from thinking someone was unfathomably beautiful and charming. That also didn't mean he would turn down any of her advances, if she did make any.

Soon the sky outside began to darken, and they collectively decided to meet up in the morning.

"See you tomorrow, then?" Claudia says with a grin, taking the priest's hand in her own.

He looks away sheepishly, "Yes, definitely."

"Mm, great!" She leans in, placing a quick kiss on each of his cheeks. Those kind of mannerisms were normally reserved for Ionians, so he wasn't really used to it. He could feel his face burning again. "Sleep well, Aven." She brings her hood up over her face, shooting him one more glance before walking away.

He takes a moment to gather his belongings, fetching his shoulder bag and tossing it over his shoulder. Giving a small wave to the few at the front desk, he strides out the door. He'd taken up residence close to the library on purpose, so his walk was brief.

As he entered his room, a wave of fatigue hit him. He'd been ignoring it all this time, but now in the comfort of his chambers, it was impossible to dismiss. He quickly headed to bed, completely ignoring his usual nightly rituals for the sake of sleep. Just as quick as he got comfortable, his mind drifted off.

The first thing that appeared to him in his dreams, was her face. Claudia. She was gorgeous. Even before her lips began to move, he could hear her angelic voice. Such bliss, hearing her soft whispers. He could hear them perfectly, but the words evaded him. All except for one...

 _"Seek."_

Her form would disappear, to be replaced with nothing but darkness. No, there was something there... His eyes just hadn't adjusted to the darkness. This was such a vivid dream that he could actually feel himself blink; As he did, the landscape before him became clear.

Before him sat the image of a dilapidated wasteland. The green sky above cast a dull light down on the blackened earth below, illuminating the silhouettes of the twisted trees and crumbling ruins. Though all seemed still, the distant horizon was alive and writhing. He shivered as a cold breeze swept past him, whispering his name. But... It _wasn't_ his name. It was something else entirely.

 _"Karthus. Seek."_

The horizon was not alive with beings... but with mist. It rolled towards him like a stampede of obsidian horses, writhing and thrashing as they threatened to tear him down. The emotion that gripped his heart was not fear... but longing. Gazing at the mist that would engulf him, he felt a burning in his chest that he recognized only to be yearning.

"Yes. Come for me." The voice that came from his mouth was alien to him, but he ignored it. He took a step forward, his bare feet sinking into the moist soil. The mist was a mere fifty yards away now. He could smell it, but the scent was indescribable. Breathing deep, his eyes felt heavy. He felt no fear, closing his eyes as the mist surrounded him. But as it did... his body was lost. All physical sensations were completely erased, and his core was left with a horrible ache. Again, he heard her voice.

 _"Seek."_

And then, nothing.


	2. Through the Night

He awoke from his rest, feeling more drained than usual. A quick glance out the window told him that it was already mid-day, and that he was to meet with Claudia very soon. He'd slept for at least twelve hours, but he still felt tired... And then he recalled the dream. Odd, considering dreams meant deep sleep. He decided not to question it.

The priest barely bothered to tidy himself, running a brush through his long hair and dressing himself in a new set of clothes. He fetched his shoulder bag, stepping out the door and locking it behind him. Making his way into the library, his eyes wandered around the space, searching for Claudia. He assumed that she'd be in the back, where they sat yesterday.

Ignoring the odd stares from the other patrons, he begins to walk to the back, the heels on his boots clacking against the wooden floor. As he rounded the corner, their eyes met. Her expression quickly changed from pleased to concerned.

"Are you okay?" She stood up, approaching him slowly. He could feel her eyes scanning over his face. Reaching up, he places his fingers across his lips. As he pulls his hand away, all lucidity he'd been missing was suddenly returned to him.

The lower half of his face was near covered in blood, most of it fresh, probably from a nosebleed. That part was still unclear. He could suddenly smell it, and taste it... The flavor was overwhelming. He stumbled back, letting out a started cry. His heart was pounding and he felt faint...

Just as he begins to act, she reaches up to touch his face. She'd retrieved a handkerchief, and was now dabbing it along his face. "Hey, calm down, it's alright." Her free hand pulled him close by the hip, holding him there firmly despite his attempt to turn away. "Here, come sit down." She takes his hand, leading him over to a chair and sitting him down.

Claudia turns away for a quick moment, dragging her chair over next to his. Sitting on the edge of it she leans over towards him, her cold hand bringing his face closer to hers. "What happened?"

"I... had a strange dream..." His voice was barely above a whisper, half-lidded eyes watching her closely. "A-About the Isles."

She licks her thumb, smudging it across his skin in an attempt to remove the red stains. "I figured you would."

"...What?"

"Mhm, there's a phenomenon regarding the Shadow Isles that makes people have visions. Basically, if you talk about them a lot, you'll start having weird dreams, and sometimes even hallucinations." As she spoke, she continued cleaning his face, much like some sort of nurse or caretaker. "You know the Harrowing? It's basically just an extension of that. Around that time of year, for whatever reason, people just start going crazy with talk of the Isles. For a good couple of weeks, everyone gets the spooks. No one really knows why it happens."

She places her hands on his cheeks, her fingertips resting on his neck. "Mm, I think I got it all." Turning around, she folds the tiny cloth into a tight square, stashing it away in her bag. "I expected it to happen, especially since you said you were researching them."

"And you didn't... warn me?"

"To be honest, I thought you'd want to experience it yourself. Sorry I didn't say anything. I didn't expect them to uh, do this." She folds her hands in her lap, still studying him.

"N-No, it's fine..." The dream itself wasn't unpleasant, in fact quite the opposite. He found that rather strange, considering this place was rumored to be filled with nightmares.

"So what was it like?" She pipes up, pursing her lips.

"It was... quite vague." He paused for a moment to collect his thoughts. "I could hear a voice..." Her voice. "...calling for me. It told me to seek, _seek_..."

"What did you see?"

"I was there, on the shore. I saw... The Black Mist. It came for me." In the books, The Black Mist was said to be instant death. It carried the creatures of the Isles to the mainland and back.

"Did it call your name?"

He glanced away, licking his lips. "Yes, but... it was not my name. And yet, _I answered_."

She looked puzzled by his response. "Then who's name was it? What did it say?"

As much as he tried, he couldn't recall the name. "I... don't remember. I'm sorry."

"Mm, no, that's fine. Just odd that it would call you something else. It's normally pretty spot-on." She sits back in her chair, crossing her arms.

He glances up at her, his eyes scanning over her outfit. She wore a black sleeveless top with a window in the middle that showed more than enough cleavage. Most men would have stared intently at that, surely, but he was not most men, in any regard. At her waist she wore a long, flowing skirt, with multiple cuts that ran up the entire length of the obsidian garment. Beneath that, a pair of sheer stockings hugged her legs, held up by a garter belt. One thing he noticed immediately was the size of her waist; It was much too small to be natural, so he assumed she was wearing a tightlaced corset beneath her top.

Surely, she'd noticed him staring for that long. In his mindless daze he'd simply lost track of time; That nosebleed sure did a number on him.

"Anyway, I'm glad you're alright now. Again, wasn't expecting all the blood." She smiles warmly, tucking her hair behind her ear. "Did you eat anything before you left? You're looking pretty pale."

My, she was rather perceptive... And caring. Those twon things normally didn't exist in the same person, he had found. "N-No, I didn't. I woke up pretty late."

"Mm, I figured. Those dreams tend to mess with your sleep schedule." Turning to reach into her bag again, she withdraws a parcel, wrapped in cloth. "Here, eat some of this." Claudia unties the knot at the top, removing the cloth and presenting the box to him.

"I-I couldn't, but thank you..." He raises a hand in protest, smiling.

"No no, I insist." The box is shoved into his chest, forcing him to grab it.

He glances up to look at her, his mouth slightly agape. "Are you sure? I-I don't want to-"

"Eat." She scolds, sitting back in her chair once more and crossing her arms. "We're not going to get anywhere with you being all lightheaded."

Exhaling, he smiles at her again, glancing down at the box. "You're right, thank you." Upon removing the lid, he's surprised to see something very familiar. Just like something out of his home town, the box is filled with rice, an assortment of vegetables, and fish. Tempura, sashimi, sushi... All of it looked incredible.

Fetching the pair of ever familiar chopsticks on the side, he begins eating, stopping only to breathe for a moment. "Mm, this is wonderful..." It tasted like home, which made him a little nostalgic. "How'd you learn to make this?"

"My family is Ionian." She says with a smile, "I'm glad you like it. Figured you would."

He nods, "Yes, very much." It doesn't take him long to polish off the rest of the box, setting the utensils and lid back in place before handing it back.

"So, miss Claudia." As she takes the box from his hands, he sits back in his seat, folding his hands in his lap. "You should tell me about yourself."

She takes a moment to stuff the box back in her bag, crossing her legs as she turns back to him. "I'm an open book. What do you want to know?"

"Well, tell me about your family. Where are you from? What do you do?"

"My family is from Ionia, but I was born here." She reaches up to run a hand through her dark hair, her lips upturning in a smile. "I don't think you want to know what I do."

He raises an eyebrow at her. " _Au contraire_. An open book reveals all its secrets, does it not?" For what reason did she have to hide her profession? Besides the obvious, of course. If she were a mercenary or an assassin, she probably wouldn't want it to be public knowledge.

"You are a holy priest, are you not?" She quips, still smiling. "My job is rather... arcane."

"Are you afraid I might judge you? After all the kindness you've shown, and all the knowledge you've shared? Please, child. _I insist._ "

Claudia uncrosses her legs, leaning in slightly. "Fine, if you must know... I'm a special kind of healer."

"Oh? And what, pray tell, is so _arcane_ about that?"

"Because I heal with sex."

His entire thought process came to a halt. Did he hear that correctly? He'd heard of physical healing before, but this was something new entirely. "I... excuse me?"

She scoffs, sitting back in her seat and turning her head away, a rather sour expression plaguing her gentle features. "Pff, thought so. I told you you didn't want to know."

He swallows hard, "I... never said that." This causes her to glance back over to him. "In fact, I'm rather intrigued as to how that all works."

Her smile returns. "Well, you know how physical healing works, right?"

Aha, so he was right to compare the two. "Yes, I am familiar with it."

"Alright, so whether you like it or not, sex is emotional. Good sex is, at least. Since it's already a physical act, the mana can be generated through touch, but since the element of emotion is added in, it also begins to heal the mind. Not only will your body feel better, you'll get a sense of clarity. It balances out the chemicals in the brain, making it easier to process information, focus clearly, and stay on track." She sounded like she really enjoyed the subject; He could hear the emotion in her voice. "Except..." Her tone suddenly shifted down. "It's not very popular. For obvious reasons."

"I mean no offense by this, but if this practice is not widely accepted, why do you intend on following this same path?"

"Because I'm fuckin' good at it, that's why!" There it was, that genuine emotion. She'd developed a bit of an accent in times of passion, but he couldn't quite pick up on where it was from. "S-Sorry."

"No no, don't apologize." Her response made him smile. He loved seeing people so... devoted to their work.

"I mean... If you're good at something, you should just go for it. Do what makes you happy, and all that."

"I agree wholeheartedly."

She sighs, "It's just... hard to find customers. In fact, it's hard to find anyone that will take me seriously."

"Mm, I'm sure you get a lot of disparagement from others." His smile faded with hers.

Claudia nods, her gaze lowering. "Yeah, unfortunately."

"I strongly believe that good things come to good people. It might take some time, but you'll get what you deserve one day, Claudia."

She rolls her eyes, "Yeah, you would say that. No offense, but I don't think you have room to talk."

"I... don't follow."

Again her eyes rise to meet him. "Don't play that with me. I know you're rich as all hell."

How she'd gotten that impression, he had no idea. He didn't dress particularly well, and although he was well-kept, so was she. However, her impression was not incorrect, as he was rather wealthy. "I... right. You're right."

The two sat in silence for a good moment. "Anyway, uh, what do you think about my practice?" She finally says, looking away.

"I think it sounds wonderful." These words brought a smile to her lips, which again, brought one to his.

"Really? You're not just... saying that, right?"

"I am not one to inspire false hopes. I think your practice sounds innovative and unique." Her smile only widened as he continued. "However, I think you should perhaps consider finding a new place of practice. Demacia isn't very... open minded."

"Pfft, tell me about it. My family thinks I'm a whore."

He laughs a little, "In a way, you are."

Her facial expression told him that she did not like that response, however. "I am not a fucking whore."

The priest held his breath, "I-I'm sorry."

Claudia exhales, laying her head back into the chair. "I hate that word."

He glanced away again, at a loss for what to say.

"There doesn't even have to be any penetration, or even fluid exchange. Sex is... more than just that. It's about making your partner feel good, physically and mentally." An exasperated sigh escapes her lips, "No one gets that. To them, sex is like, a taboo or something. But in reality, it's just human nature."

Aven nods, still unsure whether to speak or not.

"Sorry for snapping at you." She says, her gaze lowering. "I just really don't like that word... You couldn't have known any better."

"That's quite alright. I don't plan on calling you that, but I will remember it regardless."

"Thanks..." She looks back up to him again, exhaling deeply. "So uh, we should get to talking business, right? I'm sure you didn't come here to hear all about my escapades."

"As much as I indeed would love to... I would like to talk more about this dream, while it's still fresh in my mind."

"Right, yes!" She clasps her hands together excitedly before retrieving a book from her satchel. Flipping through the pages, she turns the book to face him. "Did you see this one?"

The image depicted the same centaur as he'd seen before, though in much more detail. It stood over a figure, presumably a human one, holding its halberd's sharp edge to their throat. It wore an intricate set of armor, with ghastly faces on its lower body's shoulders.

Aven shakes his head, "No, I don't recall seeing that one."

"Mm, didn't think so." She takes the book back, running her fingers over the page. "See, this one you'll probably only see in nightmares."

"You would rather call mine a dream?"

"The only difference between dreams and nightmares is fear. Did you feel scared?"

Come to think of it, he didn't actually recall feeling any fear. "...No."

"Then it was a dream. See, this is how the Isles work. They want your soul; They want everyone's souls. What better way to lure you in, than to persuade you?"

"Persuade?"

"For most people, they promise infinite power, riches, money... That kind of stuff. You said they told you to 'seek'. Now, that's a tiny bit different from the norm, but that's their way of persuading you. It could be because you seek knowledge, or perhaps just because you're really curious. The Shadow Isles KNOW you. They know what you like, and what you want." She flips through the pages, turning it to face him once more. On this page it shows a drawing of the Black Mist. At first glance one would only see the dark clouds, however if one were to squint just a little, the outlines of tortured spectres would appear within the dark image. "Like you did, most people will see the Mist. Basically the Mist can be one of two things. For a dream, it comes normally as a voice, like you said. It'll whisper sweet nothings into your ear, make you feel real good about sacrificing yourself to them. Most likely, it'll be a familiar voice, like a friend, or a family member. However, in nightmares..." She reaches over to flip the page for him. This image of the mist is much more illuminated. In the center of the writhing mass is a naked, human woman. Around her, the shapes in the mist are shown flaying her skin, blood pouring from her wounds. "...the Mist becomes a killer."

She would take the book back, after letting him stare at it for a moment. "So... Why did I have a dream, and not a nightmare?" The priest questions, crossing his arms.

"Some say it's because you have a strong soul. The Isles don't care for weak ones, so they drive them away."

He sits in silent thought for another moment, tapping his finger against his elbow mindlessly. "...And if I give them what they want?"

"They'll kill you." She states firmly, her expression remaining cold. "They'll kill you slowly, and draw the soul out of your barely living body in the most agonizing way possible."

A chill runs up his spine as she speaks. Her once passionate and daring tone had been completely replaced with cold, harsh words.

"So I wouldn't consider it." Claudia says, shrugging a little.

"I'll keep that in mind." Something within him suddenly felt... wrong. As if his soul were a puzzle, and his heart had been placed in the wrong slot; forced into a place it didn't belong, with the edges beginning to fray. He tried to ignore it, thinking it would simply go away, but it remained. Even as they continued to talk, he felt morose.

Soon, the sky outside began to darken. The two didn't even notice; That was, until the need for sustenance became an issue.

Claudia had wandered off for the moment, saying that she needed to stretch her legs, and also return her small stack of books that she'd gathered earlier. The priest laid back in his seat, his eyes falling shut. Still, he felt odd. The feeling couldn't be described by any particular word, he just felt... off. He hoped that it hadn't affected his outward display; He didn't want her worrying about it. As he heard her approach again, he sat up.

"It's already dark out." Claudia says with a smile, bending over to fetch her bag. "I can't believe I lost track of time like that. I'm starving."

"You were the one who insisted on giving me your lunch." He grins, running a hand through his hair.

"Yep, and I don't regret a thing." She suddenly jumps a bit, as if an idea had come to mind. "And I know exactly how you can repay me for my kindness..." Without warning, she plops down in his lap, turning to her side and tossing an arm around his neck. "How 'bout you take me out to dinner, hmm?"

"I uh, sure...?" He had enough money to go around, so that was of no object. "Where would you want to go?"

"Mm, I dunno, where can we go?" She bounces up and down a little in excitement, her smile widening. "I can think of a few places."

"Wherever you want." Being this close to her was strange to him, but he didn't hate it. Normally physical contact was not his forte, but he supposed an exception was needed for someone as generous as her.

"You wanna go somewhere nice? We'll have to find you a new shirt." She places her fingertip upon the bit of blood that had stained his robes.

"If you want, sure."

"Mm, great!" She places a tiny kiss on his cheek, jumping up and tossing her bag over her shoulder. "Hurry up, or I'm gonna have to eat you."

The kiss caught him off guard, but he had no time to react. "Yes, madam." He says mockingly, standing up to follow her. The two walk out of the building together, greeted by the cool outside air as they exit.

"So uh, should we swing by your place first? Unless you want me to dress you." She snickers, her eyes narrowing at him.

"N-No thank you, I don't think I could quite fill out your clothes." He laughs a little, "My room is just a minute away, so I suppose we'll go there first, since you're so set on something fancy." He didn't even know if any of his clothes could be considered formal, but most places didn't really mind anyway. An obvious blood stain was not as widely accepted, however.

"Pfft. I think you'd look great in a corset." She snakes an arm around his waist, pulling it tight. "Men look incredible in them, I think."

The priest couldn't help but to smirk, turning his head away. "Perhaps another time, my dear."

"I'll keep you to that!"


End file.
